1. Field of the Art
The present invention relates generally to an apparatus comprising a conveyer system for transferring circuit substrates of printed-circuit boards, and a substrate positioning device for positioning the circuit substrates at predetermined positions. More particularly, the invention relates to such a conveying and positioning apparatus which is capable of handling the circuit substrates of different sizes of the printed-wiring boards.
2. Related Art Statement
In the art of manufacturing printed-wiring boards, circuit substrates of the boards are generally transferred by a suitable conveyer system successively to a substrate positioning device designed to position each of the received substrates at predetermined positions at which holes are drilled in the substrate, or at which electronic circuit components are placed on the substrate. Such an apparatus for conveying and positioning the substrates is also used for inspecting the printed-wiring boards after the placement of the electronic components thereon, or for performing other operations on the substrates in an automatic fashion.
The conveyer system functions to load the positioning device with the substrates, and to unload the positioning device after the substrates have been processed on the positioning device. An example of such a conveyer system includes a pair of parallel side frames which are spaced from each other and at least one of which is movable toward and away the other. The substrates of a printed-wiring board are transferred to and from the positioning device while being guided by the side frames. In this type of conveyer system, the distance between the parallel spaced-apart side frames can be changed by moving the movable side frame relative to the other, whereby the conveyer system is capable of handling the circuit substrates of printed-wiring boards having different sizes.
An example of the substrate positioning device comprises a mounting or support member which is moved by a driving device along an X axis parallel to the spaced-apart side frames of the conveyer system, and a Y axis perpendicular to the X axis. The support member supports a pair of holder members for supporting the substrate. The holder members extend in the X-axis direction, and at least one of the holder members is movable in the Y-axis direction toward and away from the other, so that the two spaced-apart holder members are engageable with opposite sides of the substrate parallel to the X axis, to thereby position and hold the substrate in the Y-axis direction. Thus, like the above-indicated conveyer system, the distance between the holder members can be adjusted to suit the specific size of the substrate to be positioned, by moving the holder members toward or away from each other in the Y-axis direction.
3. Problems Solved By the Invention
However, the above-indicated conveyer system and substrate positioning device are designed independently of each other, in respect of the arrangements for changing the distance between the side frames and the distance between the substrate holder members. That is, the distance changing arrangements of the conveyer system and the positioning device are not interconnected, and must be operated separately from each other. Hence, considerable time is required to adjust the above-indicated distances of the conveyer system and the positioning device. Further, large efforts are needed if the adjustments of the distances are made manually by the operator. If a suitable mechanism such as a screw-and-nut arrangement is employed for adjusting the distance, such a mechanism is needed for both the side frames of the conveyer system and the holder members of the positioning device. Consequently, the conveyer and positioning apparatus is complicated, and the cost of manufacture is accordingly increased.